<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      left-arrow
      title="黑马头条"
      @click-left="$router.back()"
    ></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div class="loading-wrap" v-if="loading">
        <van-loading
          color="#3296fa"
          vertical
        >加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div class="article-detail" v-else-if="articles.title">
        <!-- 文章标题 -->
        <h1 class="article-title">{{articles.title}}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="articles.aut_photo"
          />
          <div slot="title" class="user-name">{{articles.aut_name}}</div>
          <div slot="label" class="publish-date">{{articles.pubdate | relativeTime}}</div>
          <!-- 关注取消关注组件化处理 -->
          <!-- 一个组件上面的class类，会被组件的跟标签继承过去使用，所以我们只需要调整组件上面的class，就可以去修改组件模板里面的央视 -->
          <FollowUser
          class="follow-btn"
          :isFollowed="articles.is_followed"
          :userId="articles.aut_id"
          @updateFollow="articles.is_followed = $event"></FollowUser>
           <!-- <van-button
            v-if="articles.is_followed"
            class="follow-btn"
            round
            size="small"
            :loading="followLoading"
            @click="onFollow" >已关注</van-button>
          <van-button
            v-else
            class="follow-btn"
            type="info"
            color="#3296fa"
            round
            size="small"
            icon="plus"
           @click="onFollow" >关注</van-button> -->

        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div class="article-content markdown-body"  ref="article-content" v-html="articles.content"></div>
        <van-divider>正文结束</van-divider>
        <!-- -----------------------------------------文章评论列表 -->
        <commentList @replyClick="onReply" :list="commentList" :source="articles.art_id"></commentList>
        <!-- -----------------------------------------文章评论列表 -->
        <!-- 底部区域 -->
        <div class="article-bottom">
            <van-button
                class="comment-btn"
                type="default"
                round
                size="small"
                @click="isPostShow = true"
              >写评论</van-button>
            <van-icon
                name="comment-o"
                :info="articles.comm_count"
                color="#777"
              />
            <van-icon
                color="#777"
                name="star-o"
            />
            <van-icon
                color="#777"
                name="good-job-o"
              />
            <van-icon name="share" color="#777777"></van-icon>
        </div>
        <!-- /底部区域 -->
        <!-- -----------发布评论 ----------------------->
        <van-popup v-model="isPostShow" position="bottom">
          <commentPost  :target="articles.art_id" @postSuccess="onPostSuccess"></commentPost>
        </van-popup>
        <!-- -----------发布评论 ----------------------->
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div class="error-wrap" v-else-if="errStatus === 404">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div v-else class="error-wrap">
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button class="retry-btn" @click="loadArticles">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>
    <!-- -----------评论回复 ----------------------->
    <!-- 问题：每次打开评论回复弹层，内容不断更新，始终是第一次的内容 -->
    <!-- 原因：弹层组件中的内容默认打开一次后，就不会销毁而是频繁的进行display：none/block导致组件不会重新创建 -->
    <!-- 解决：给pop弹层中的组件添加v-if指令，强制让内容组件进行重建和销毁，内容就会更新 -->
      <van-popup v-model="isReplyShow" position="bottom"  style="height: 100%">
        <commentReply v-if="isReplyShow" :comment="currentComment"  @close="isReplyShow = false"></commentReply>
      </van-popup>
    <!-- -----------评论回复 ----------------------->
  </div>
</template>

<script>
import { getArticleById } from '@/api/article'
import { ImagePreview } from 'vant'
// 数组接收图片路径，然后展示预览
// startPosition 选项指定图片的初始位置（索引值）起始的位置从零开始
// 通过 onClose 选项监听图片预览的关闭事件。
import FollowUser from '@/components/follow-user/index.vue'
import commentList from './components/comment-list'
import commentPost from './components/comment-post'
import commentReply from './components/comment-reply'
export default {
  name: 'ArticleIndex',
  // 依赖注入
  provide: function () {
    return {
      articleId: this.articleId
    }
  },
  components: {
    FollowUser,
    commentList,
    commentPost,
    commentReply
  },
  props: {
    // 使用props获取动态路由的数据
    articleId: {
      type: [Number, String, Object],
      required: true
    }
  },
  data () {
    return {
      articles: {},
      loading: true,
      errStatus: 0,
      isPostShow: false,
      commentList: [], // 评论列表数据
      isReplyShow: false,
      currentComment: {} // 存储每次点击回复的评论对象
    }
  },
  computed: {},
  watch: {},
  created () {
    this.loadArticles()
  },
  mounted () {},
  methods: {
    async loadArticles() {
      try {
        // 自定义抛出错误
        // if (Math.random() > 0.5) {
        //   JSON.parse('dsankljdnskaljndlkjsa')
        // }
        const { data } = await getArticleById(this.articleId)
        // console.log(data)
        this.articles = data.data
        // 初始化图片预览
        // console.log(this.$refs['article-content'])
        setTimeout(() => {
          // console.log(this.$refs['article-content'])
          this.previewImage()
        })
      } catch (err) {
        console.log(err)
        if (err.response && err.response.status === 404) {
          this.errStatus = 404
        }
      }
      this.loading = false
    },
    // 预览图片处理事件函数
    previewImage() {
      const articleContent = this.$refs['article-content']
      const imgs = articleContent.querySelectorAll('img')
      //  console.log(imgs);
      const images = []
      imgs.forEach((item, index) => {
        images.push(item.src)
        item.onclick = () => {
          ImagePreview({
            //  后push 进images的数组
            images,
            //  照片的起始位置 数组的第0个
            startPosition: index,
            onClose() {
              this.$toast('图片已关闭!')
            }
          })
        }
      })
    },
    // 处理发布评论成功事件子传父
    onPostSuccess(obj) {
      // 发布成功后关闭弹层
      this.isPostShow = false
      console.log(obj)
      this.commentList.unshift(obj)
    },
    // 孙子组件点击回复功能
    onReply(comment) {
      this.isReplyShow = true
      console.log(comment)
      this.currentComment = comment
    }
  }
}
</script>

<style scoped lang="less">
@import "./github-markdown.css";
.article-container {

  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
